<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* 外边距，在两个盒子之间得外边距会发生重合而不是分开设置 */
        .up {
            width: 200px;
            height: 200px;
            background-color: pink;
            margin-bottom: 50px;
        }

        .down {
            width: 200px;
            height: 200px;
            background-color: aquamarine;
            margin-top: 100px;
        }
    </style>
</head>
<body>
    <div class="up">1</div>
    <div class="down">2</div>
</body>
</html>